See our Guidance notes, page 6, paragraph 2. When filling in your forms people want the information they need there and then. Put yourself in the form users position and think about which questions they might have a problem with. Provide examples of the sorts of answers you are looking for, and where appropriate, provide guidance notes as near as possible to the question they relate to (i.e. in the actual form).

A light shade of a colour, like blue, across the whole background of a form relieves the eye from the harshness of a stark white background. And if the answer spaces people have to fill in are white, the tinted background both cues them in to where they write, and allows them to visually sense how much they have to fill in.